Gents, Long time lurker first time poster. Here are a few things to remember when cooking brisket. (or all meats for that matter)
Probe in one spot. Stick in in the thickest part of the center and go half way in. Every time you probe the meat and remove it your poking a whole in your bark, which is keeping all of the juices in. Juices will gush out of the meat and render it dry.
Secondly, pull it at 180 and let it rest for 45-60 minutes wrapped in foil. The meat will continue to cook approximately 5 to 10 more degrees. (especially on a hot cook of over 300 you won't see the same kind of rise in temp when resting on a cook at temps of 250) DO NOT, I repeat do not pull the probe. Foil around it. The longer resting time will assure the juices stay in the meat and not on the cutting board. Be patient. You will be rewarded
Third, if your buying cryo-vac briskets from Costco, don't trim to much of the fat off the top. If there is very little fat on it like a trimmed brisket at the local grocery store ask the meat dept. for some extra fat or go for some bacon and place it on top while cooking.
Try those instructions out and you should have better luck on your next cook. Your meat does look overcooked. You should be able to pull it apart and still have some give to it.
Your smoke ring and bark however, are money. Great color and texture! Thanks for posting with a picture.